mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-07 02:54:09 +08:00
169113ece0
The ARM Linux kernel handles the EABI syscall numbers as follows: 0 - NR_SYSCALLS-1 : Invoke syscall via syscall table NR_SYSCALLS - 0xeffff : -ENOSYS (to be allocated in future) 0xf0000 - 0xf07ff : Private syscall or -ENOSYS if not allocated > 0xf07ff : SIGILL Our compat code gets this wrong and ends up sending SIGILL in response to all syscalls greater than NR_SYSCALLS which have a value greater than 0x7ff in the bottom 16 bits. Fix this by defining the end of the ARM private syscall region and checking the syscall number against that directly. Update the comment while we're at it. Cc: <stable@vger.kernel.org> Cc: Dave Martin <Dave.Martin@arm.com> Reported-by: Pi-Hsun Shih <pihsun@chromium.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
122 lines
3.3 KiB
C
122 lines
3.3 KiB
C
/*
|
|
* Based on arch/arm/kernel/sys_arm.c
|
|
*
|
|
* Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
|
|
* Copyright (C) 1995, 1996 Russell King.
|
|
* Copyright (C) 2012 ARM Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/compat.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/signal.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/system_misc.h>
|
|
#include <asm/unistd.h>
|
|
|
|
static long
|
|
__do_compat_cache_op(unsigned long start, unsigned long end)
|
|
{
|
|
long ret;
|
|
|
|
do {
|
|
unsigned long chunk = min(PAGE_SIZE, end - start);
|
|
|
|
if (fatal_signal_pending(current))
|
|
return 0;
|
|
|
|
ret = __flush_cache_user_range(start, start + chunk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
cond_resched();
|
|
start += chunk;
|
|
} while (start < end);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline long
|
|
do_compat_cache_op(unsigned long start, unsigned long end, int flags)
|
|
{
|
|
if (end < start || flags)
|
|
return -EINVAL;
|
|
|
|
if (!access_ok(VERIFY_READ, (const void __user *)start, end - start))
|
|
return -EFAULT;
|
|
|
|
return __do_compat_cache_op(start, end);
|
|
}
|
|
/*
|
|
* Handle all unrecognised system calls.
|
|
*/
|
|
long compat_arm_syscall(struct pt_regs *regs)
|
|
{
|
|
unsigned int no = regs->regs[7];
|
|
void __user *addr;
|
|
|
|
switch (no) {
|
|
/*
|
|
* Flush a region from virtual address 'r0' to virtual address 'r1'
|
|
* _exclusive_. There is no alignment requirement on either address;
|
|
* user space does not need to know the hardware cache layout.
|
|
*
|
|
* r2 contains flags. It should ALWAYS be passed as ZERO until it
|
|
* is defined to be something else. For now we ignore it, but may
|
|
* the fires of hell burn in your belly if you break this rule. ;)
|
|
*
|
|
* (at a later date, we may want to allow this call to not flush
|
|
* various aspects of the cache. Passing '0' will guarantee that
|
|
* everything necessary gets flushed to maintain consistency in
|
|
* the specified region).
|
|
*/
|
|
case __ARM_NR_compat_cacheflush:
|
|
return do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]);
|
|
|
|
case __ARM_NR_compat_set_tls:
|
|
current->thread.uw.tp_value = regs->regs[0];
|
|
|
|
/*
|
|
* Protect against register corruption from context switch.
|
|
* See comment in tls_thread_flush.
|
|
*/
|
|
barrier();
|
|
write_sysreg(regs->regs[0], tpidrro_el0);
|
|
return 0;
|
|
|
|
default:
|
|
/*
|
|
* Calls 0xf0xxx..0xf07ff are defined to return -ENOSYS
|
|
* if not implemented, rather than raising SIGILL. This
|
|
* way the calling program can gracefully determine whether
|
|
* a feature is supported.
|
|
*/
|
|
if (no < __ARM_NR_COMPAT_END)
|
|
return -ENOSYS;
|
|
break;
|
|
}
|
|
|
|
addr = (void __user *)instruction_pointer(regs) -
|
|
(compat_thumb_mode(regs) ? 2 : 4);
|
|
|
|
arm64_notify_die("Oops - bad compat syscall(2)", regs,
|
|
SIGILL, ILL_ILLTRP, addr, no);
|
|
return 0;
|
|
}
|